The present invention relates to an industrial robot provided with a function to output the input from a safety device to external equipment.
Recently, there is a strong demand for an industrial robot improved in safety and maintenance.
Generally, an industrial robot is provided with a function to transmit the input to a safety device in order to immediately stop the robot, and a function to output the input from the safety device to external equipment. The configuration of a conventional industrial robot is shown in FIG. 3 and FIG. 4. FIG. 3 is a circuit diagram of a safety device for a conventional robot. FIG. 4 is a block diagram of a conventional safety device.
In FIG. 3 and FIG. 4, a conventional industrial robot is provided with a robot body 18 and a safety device. The safety device serves a function to immediately stop the robot. The safety device includes a safety fence 12 and an input means. As the input means, for example, there are provided an emergency switch 11, a switch to check for opening/closing of the safety fence, and a deadman""s switch 13 or like switches.
A contact type input means is generally used as an input means, and at the same time, a xe2x80x9cbxe2x80x9d contact is employed. The xe2x80x9cbxe2x80x9d contact is closed during normal service, and the contact opens when an emergency switch or the like is pressed.
Also, the industrial robot includes an output device 15 which outputs the input from the safety device to external equipment in order to immediately stop peripheral equipment 14 (e.g. a welder) according to the actuation of the safety device. That is, when the safety device is actuated, the peripheral equipment 14 will be immediately stopped by the output from the output device 15.
In such prior art output device 15, when a plurality of robot bodies are used, with both output means and input means of the safety device connected to all the plurality of robot bodies, and the safety device is actuated on one robot, then all the plurality of robots in operation will stop immediately.
In such prior art industrial robot, there will arise problems as described in the following.
In case a safety device is connected to peripheral equipment and it is necessary to initialize the safety device after recovery of the output from the safety device, the peripheral equipment must be initialized each time when the safety device is restored to its original condition after actuation of the safety device. Accordingly, it will take much time to restore the industrial robot to normal operation.
Also, a plurality of robots are used, and both input means and output means of the safety device are connected to the plurality of robot bodies so that all the robots then used will immediately stop when the safety device is actuated on any one of the plurality of robot bodies. In that case, a closed circuit is formed in the entire industrial robot system with respect to the output from the safety device, causing the industrial robot system to be deadlocked. As a result, it becomes very difficult to restore the industrial robot to normal operation.
The present invention provides an industrial robot improved in both maintenance and safety.
An industrial robot of the present invention comprises:
a robot body,
a plurality of safety devices to stop the operation of the robot body,
connecting portions disposed between respective ones of the plurality of safety devices, and
an output means to transmit output data to external equipment.
The safety devices are connected in series to each other, and the output means is removably connected to the connecting portion.
With this configuration, the industrial robot will be improved in both maintenance and safety.